Method of handling access network discovery and selection function and related communication device

ABSTRACT

A method of handling an access network discovery and selection function (ANDSF) for a network of a wireless communication system is disclosed. The method comprises determining a first plurality of closed subscriber group (CSG) cells of the wireless communication system with a first CSG identity, for a mobile device of the wireless communication system to communicate with an evolved packet core (EPC) network of the wireless communication system via the first plurality of CSG cells, after the network determines the 3rd Generation Partnership Project (3GPP) as an access technology for the mobile device; and configuring an inter-system mobility policy (ISMP) node such that a value of an AccessTechnology leaf of a PrioritizedAccess node is configured as the 3GPP, and a value of a first AccessId leaf of the PrioritizedAccess node is configured as the first CSG identity of the first plurality of CSG cells.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/505,529, filed on Jul. 7, 2011 and entitled “Method for theenhancement of ANDSF for IP flow mobility”, the contents of which areincorporated herein in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method used in a wirelesscommunication system and related communication device, and moreparticularly, to a method of handling an access network discovery andselection function and related communication device.

2. Description of the Prior Art

A long-term evolution (LTE) system supporting the 3GPP Rel-8 standardand/or the 3GPP Rel-9 standard are developed by the 3rd GenerationPartnership Project (3GPP) as a successor of a universal mobiletelecommunications system (UMTS), for further enhancing performance ofthe UMTS to satisfy increasing needs of users. The LTE system includes anew radio interface and a new radio network architecture that provides ahigh data rate, low latency, packet optimization, and improved systemcapacity and coverage. In the LTE system, a radio access network knownas an evolved universal terrestrial radio access network (E-UTRAN)includes multiple evolved Node-Bs (eNBs) for communicating with multipleUEs, and communicates with a core network (e.g., evolved packet core(EPC) network) including a mobility management entity (MME), a servinggateway, etc., for Non Access Stratum (NAS) control.

Besides, a closed subscriber group (CSG) is defined in the 3GPPstandards, for managing CSG cells (e.g., femto cells). In detail, eachCSG cell is identified by a CSG identity, and multiple CSG cells mayshare a same CSG identity. The UE can determine whether it can access aCSG cell (e.g., communicate with the EPC network via the CSG cell) bychecking a CSG identity of the CSG cell. Further, a CSG cell can beconfigured to operate in a CSG mode, to allow only a limited set of UEsto access the CSG cell. Alternatively, a CSG cell can be configured tooperate in an open access mode, to allow all UEs to access the CSG cell.

An access network discovery and selection function (ANDSF) is a newnetwork entity located (e.g., operated) in a home public land mobilenetwork (PLMN) of a UE as a Home-ANDSF (H-ANDSF), or in a visited PLMNof the UE as a Visited-ANDSF (V-ANDSF). The ANDSF is used for providingassistance data of network discovery and selection according tooperators' policy. The ANDSF shall respond to a request transmitted by aUE for accessing network discovery information (pull mode operation), orinitiate data transfer to the UE (push mode operation), according tonetwork triggers or a result of previous communications with the UE. Indetail, an inter-system mobility policy (ISMP), provided by the ANDSF,is used for describing operator-defined rules and preferences that mayaffect inter-system mobility decisions taken by the UE. For example,when the UE intends to route IP traffic only over a single radiointerface, the inter-system mobility policy can be considered, to decidewhen inter-system mobility is allowed (or restricted) and/or to selectan access technology type and/or an access network which is the mostpreferable. On the other hand, an inter-system routing policy (ISRP),provided by the ANDSF, is used for describing inter-system routingpolicies according to which the UE can route IP traffic over multipleradio interfaces simultaneously. For example, the UE can decide whetheran access technology type and/or access network is restricted to aspecific IP traffic flow and/or a specific APN. The UE may also selectan access technology type and/or an access network which is the mostpreferable.

Therefore, the ANDSF can provide ISMP policies to a UE, for assistingthe UE to perform network discovery and selection according tooperators' policies. Further, the ANDSF provides the ISMP policies for apreferred access technology to the UE under that validityArea provideslocation information including PLMN, LAC, TAC, GERAN_CI, UTRAN_CI,EUTRA_CI, etc. For example, when the UE is a specific CSG member andlocated in coverage of a marco EUTRA cell and a group of CSG cells witha specific CSG identity, the ANDSF can only provide routing policies infavor of a PrioritizedAccess between a 3GPP access technology andnon-3GPP access technologies (e.g., WLAN with a SSID) or between cellsin the 3GPP access technology under that the ValidityArea provides aspecific cell identity.

However, a home access network scenario is not considered in the priorart. In detail, if the UE enters coverage of a group of CSG cells withthe same CSG ID, the ANDSF can only provide a list of routing policieswith ValidityArea configured to each cell ID. The routing policies arevalid only when the UE is using a cell with a cell ID specified in thevalidityArea. Handling of the routing policies is complicated and is notnecessary. Further, the UE may be in coverage of multiple CSG cells withdifferent CSG IDs, wherein some of the CSG cells may have differentcapabilities. The ANDSF does not allow an operator to provide a routingpolicy with a preferred access technology configured as the 3GPP accesstechnology with a specific CSG ID.

On the other hand, when the UE is handed over from a Marco cell to a CSGcell, an existing packet data network (PDN) connection of the UE remainsconnecting to a PDN gateway (P-GW) in an EPC network via a home eNBaccording to the prior art. If a home network equips with a localgateway (L-GW), the ANDSF lacks an applicable leaf for providingoffloading policies to the UE, so as to route PDN connections of the UEfrom the P-GW in the EPC network to the L-GW in the home network.

Besides, according to the prior art, an operator uses ISRP to influencea UE to select between a 3GPP access technology and non-seamless (NS)WLAN offload, for routing a specific PDN connection associated to aspecific APN) according to multi access PDN connectivity (MAPCON)polices or NS-WLAN offload policies, or routing specific IP flowsaccording to IP Flow Mobility and Seamless Offload (IFOM) policies.

However, when the UE has multiple PDN connections, the ANDSF lacksapplicable leafs for providing offloading policies to the UE, for the UEto select a specific IP interface identified by associated APN forrouting specific IP flows. For example, the UE has multiple PDNconnections via the same access network to the EPC network (e.g., PDN1associated with APN1 for evolved packet system (EPS) services and PDN2associated with APN2 for IP multimedia subsystem (IMS) services) or thehome network (e.g., PDN1 associated with APN1 via the EPC network andPDN2 associated to APN2 via the L-GW in the home Network). Based on thecurrent ISRP policies, there is no routing policy according to which theUE can route a specific PDN connection or a specific IP flow in theabove scenarios.

Therefore, how to solve abovementioned problems is a topic to bediscussed and addressed.

SUMMARY OF THE INVENTION

The present invention therefore provides a method and relatedcommunication device for handling an access network discovery andselection function to solve the abovementioned problem.

A method of handling an access network discovery and selection function(ANDSF) for a network of a wireless communication system is disclosed.The method comprises determining a first plurality of closed subscribergroup (CSG) cells of the wireless communication system with a first CSGidentity, for a mobile device of the wireless communication system tocommunicate with an evolved packet core (EPC) network of the wirelesscommunication system via the first plurality of CSG cells, after thenetwork determines the 3rd Generation Partnership Project (3GPP) as anaccess technology for the mobile device; and configuring an inter-systemmobility policy (ISMP) node such that a value of an AccessTechnologyleaf of a PrioritizedAccess node is configured as the 3GPP, and a valueof a first AccessId leaf of the PrioritizedAccess node is configured asthe first CSG identity of the first plurality of CSG cells.

A method of handling an access network discovery and selection function(ANDSF) for a network of a wireless communication system is disclosed.The method comprises determining a plurality of closed subscriber group(CSG) cells of the wireless communication system with a CSG identity,for the a mobile device of the wireless communication system to access afirst service indicated by a first access point name (APN) of thewireless communication system via the plurality of CSG cells with theCSG identity, after the network determines the 3GPP as an accesstechnology for the mobile device; and configuring an inter-systemmobility policy (ISMP) node such that a value of an AccessTechnologyleaf of a PrioritizedAccess node is configured as the 3rd GenerationPartnership Project (3GPP), a value of an AccessId leaf of thePrioritizedAccess node is configured as the CSG identity of theplurality of CSG cells, and a PrioritizedAPN node is configured underthe ISMP node for configuring the first APN.

A method of handling an access network discovery and selection function(ANDSF) for a network of a wireless communication system is disclosed.The method comprises determining an IP flow of a mobile device of thewireless communication system, which is with a packet data network (PDN)connection associated to an access point name (APN) of the wirelesscommunication system, for the mobile device to route the IP flow; andconfiguring an inter-system routing policy (ISRP) policy for aForFlowBased node such that a value of an AccessTechnology leaf of aRoutingRule node is configured as the 3rd Generation Partnership Project(3GPP), a value of an AccessId leaf is configured as a CSG identity of aplurality of CSG cells, and a PrioritizedAPN node is configured under apolicy node for configuring the APN.

A method of handling an access network discovery and selection function(ANDSF) for a mobile device in a wireless communication system isdisclosed. The method comprises receiving at least one policy from anetwork of the wireless communication system; checking a RoutingCriterianode for location of the UE, for determining a validity criteria of apolicy according to an AccessTechnology node of a RoutingRule node, toselect at least one valid policy from the at least one policy; andselecting one of the at least one valid policy, for communicating withthe network.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a wireless communication systemaccording to an example of the present invention.

FIG. 2 is a schematic diagram of an ANDSF according to an example of thepresent invention.

FIG. 3 is a schematic diagram of a communication device according to anexample of the present invention.

FIG. 4 is a flowchart of a process according to an example of thepresent invention.

FIG. 5 is a schematic diagram of a policy node according to an exampleof the present invention.

FIG. 6 is a schematic diagram of a policy node according to an exampleof the present invention.

FIG. 7 is a schematic diagram of a DiscoveryInformation node accordingto an example of the present invention.

FIG. 8 is a schematic diagram of a UE_Location node according to anexample of the present invention.

FIG. 9 is a schematic diagram of a policy node according to an exampleof the present invention.

FIG. 10 is a flowchart of a process according to an example of thepresent invention.

FIG. 11 is a flowchart of a process according to an example of thepresent invention.

FIG. 12 is a flowchart of a process according to an example of thepresent invention.

DETAILED DESCRIPTION

Please refer to FIG. 1, which is a schematic diagram of a wirelesscommunication system 10 according to an example of the presentinvention. The wireless communication system 10 is briefly composed of anetwork 111 and a plurality of user equipments (UEs). In FIG. 1, thenetwork 111 and the UEs are simply utilized for illustrating thestructure of the wireless communication system 10. Practically, thenetwork 111 can be a universal terrestrial radio access network (UTRAN)comprising a plurality of Node-Bs (NBs) in a universal mobiletelecommunications system (UMTS). Alternatively, the network 111 can bean evolved UTRAN (E-UTRAN) comprising a plurality of evolved NBs (eNBs)and/or relays in a long term evolution (LTE) system or a LTE-Advanced(LTE-A) system. The UTRAN/EUTRAN can be used for building macrocells,picocells or femtocells, to cover geographic areas with various sizes.Alternatively, the network 111 can be a wireless local area network(WLAN) (e.g., WiFi) comprising one or more access points (APs).

Furthermore, the network 111 can also include both the UTRAN/E-UTRAN anda core network (e.g., an evolved packet core (EPC) network), wherein thecore network includes network entities such as a Mobility ManagementEntity (MME), a Serving Gateway (S-GW), a Packet Data Network (PDN)Gateway (P-GW), and/or a local gateway (L-GW). In other words, after thenetwork 111 receives information transmitted by a UE, the informationmay be processed only by the UTRAN/E-UTRAN and decisions correspondingto the information are made at the UTRAN/E-UTRAN. Alternatively, theUTRAN/E-UTRAN may forward the information to the core network, and thedecisions corresponding to the information are made at the core networkafter the core network processes the information. Besides, theinformation can be processed by both the UTRAN/E-UTRAN and the corenetwork, and the decisions are made after coordination and/orcooperation are performed by the UTRAN/E-UTRAN and the core network. Thenetwork 111 is capable of executing an access network discovery andselection function (ANDSF), for providing assistance data of networkdiscovery and selection according to operators' policy. That is, theANDSF can be realized by a dedicated ANDSF server in the network 111, orcan be realized as a function in a network entity such as the NB, theeNB and/or the relay node in the network 111. Thus, when it is statedthat a following example is realized by the network 111, it means thatthe following example is realized by the dedicated ANDSF server and/orthe network entity in the network 111.

Please refer to FIG. 2, which is a schematic diagram of an ANDSF 20according to an example of the present invention. The ANDSF 20 caninclude possible nodes and leaves such as a policy node, aDiscoveryInformation node, a UE_Location node and an inter-systemrouting policy (ISRP) node. Further, the policy node can be referred toas an inter-system mobility policy (ISMP) node and the ISRP node whichcan be a parent node accommodating one or more policy nodes such as aForFlowBased node, a ForServiceBased node and a ForNonSeamlessOffloadnode. In short, the ISMP node, the ForFlowBased node, theForServiceBased node and the ForNonSeamlessOffload node are all policynodes which contain policies, e.g. routing information, for the UE todetermine which access technology to use, e.g., based on policies in theISMP node, or how to distribute traffic among available accesses, e.g.based on policies in the ForFlowBased node, the ForServiceBased node orthe ForNonSeamlessOffload node. The ANDSF 20 is simply used forillustrating possible realizations of the ANDSF, and may includeadditional nodes and leaves which are not limited herein.

The UEs can be mobile phones, laptops, tablet computers, electronicbooks, and portable computer systems. The UEs can also be referred tomobile stations (MSs) or user equipments (UEs) in the UMTS, the LTEsystem or the LTE-A system. Besides, the network 111 and a UE can beseen as a transmitter or a receiver according to transmission direction,e.g., for an uplink (UL), the UE is the transmitter and the network 111is the receiver, and for a downlink (DL), the network 111 is thetransmitter and the UE is the receiver.

Please refer to FIG. 3, which is a schematic diagram of a communicationdevice 30 according to an example of the present invention. Thecommunication device 30 can be a UE or the network 111 shown in FIG. 1,but is not limited herein. The communication device 30 may include aprocessing means 300 such as a microprocessor or Application SpecificIntegrated Circuit (ASIC), a storage unit 310 and a communicationinterfacing unit 320. The storage unit 310 may be any data storagedevice that can store a program code 314, accessed and executed by theprocessing means 300. Examples of the storage unit 310 include but arenot limited to a subscriber identity module (SIM), read-only memory(ROM), flash memory, random-access memory (RAM), CD-ROM/DVD-ROM,magnetic tape, hard disk and optical data storage device. Thecommunication interfacing unit 320 is preferably a transceiver and isused to transmit and receive signals according to processing results ofthe processing means 300.

Please refer to FIG. 4, which is a flowchart of a process 40 accordingto an example of the present invention. The process 40 is utilized inthe network 111 (i.e., the ANDSF server therein) shown in FIG. 1, forhandling the ANDSF 20 shown in FIG. 2. The process 40 may be compiledinto the program code 314 and includes the following steps:

Step 400: Start.

Step 402: Determine a plurality of closed subscriber group (CSG) cellsof the wireless communication system 10 with the same CSG identity, fora UE to communicate with an EPC network of the wireless communicationsystem via the plurality of CSG cells, after the network 111 determinesthe 3rd Generation Partnership Project (3GPP) as an access technologyfor the UE.

Step 404: Configure an ISMP node such that a value of anAccessTechnology leaf of a PrioritizedAccess node is configured as the3GPP, and a value of an AccessId leaf of the PrioritizedAccess node isconfigured as the same CSG identity of the plurality of CSG cells.

Step 406: End.

According to the process 40, the network 111 first determines aplurality of CSG cells of the wireless communication system 10 with thesame CSG identity, for a UE to communicate with an EPC network of thewireless communication system via the plurality of CSG cells, after thenetwork determines the 3GPP as an access technology for the UE. Then,the network 111 configures an ISMP node such that a value of anAccessTechnology leaf of a PrioritizedAccess node is configured as the3GPP, and a value of an AccessId leaf of the PrioritizedAccess node isconfigured as the same CSG identity of the plurality of CSG cells. Inother words, after the CSG identity is determined by the network 111,the 3GPP and the CSG identity of the CSG cells are configured (i.e.,specified) in the ISMP node. Thus, according to the process 40, when thenetwork 111 determines the 3GPP as an access technology for the UE, thenetwork 111 can configure a CSG identity, to indicate the CSG cells withthe CSG identity to the UE. As a result, the UE can communicate with theEPC network via the CSG cells.

For example, assuming that a CSG identity of a plurality of CSG cells isCSG-ID1, according to the process 40, an xml code for the ISMP node canbe configured by the network 111 as follows:

<X>/Policy/<X>/PrioritizedAccess/<X>/AccessTechnology: 3GPP<X>/Policy/<X>/PrioritizedAccess/<X>/AccessId: CSG-ID1

Please refer to FIG. 5, which is a schematic diagram of a policy node 50according to an example of the present invention. FIG. 5 is used forillustrating configuration (e.g., modification and addition) of nodesand leaves corresponding to the xml code. As shown in FIG. 5, theAccessTechnology leaf 500 and the AccessId leaf 502 are configured(i.e., specified) as the 3GPP and the CSG-ID1, respectively.

Please note that, a spirit of the process 40 is that when the network111 determines the 3GPP as an access technology for the UE, the networkconfigures a CSG identity, to indicate the CSG identity to the UE whichmay be the member of the CSG with the CSG identity, such that the UE cancommunicate with the EPC network via CSG cells with the CSG identity.Realization of the process 40 is not limited. For example, policies ofthe PrioritizedAccess node, which includes the AccessTechnology leafconfigured as the 3GPP and the AccessId leaf configured as the CSGidentity, can be provided by the policy node, e.g., the ISMP node, theForFlowBased node, the ForServiceBased node and theForNonSeamlessOffload node, as shown in FIG. 2.

Please note that, even though the policy node is used in the followingexamples for illustrating the present invention, the policy node can bereplaced by the other policy nodes including the ForFlowBased node, theForServiceBased node or the ForNonSeamlessOffload node, i.e., thefollowing examples can be applied to the ForFlowBased node, theForServiceBased node and the ForNonSeamlessOffload node.

For example, the network 111 can configure a policy node under the ISRPnode, e.g., a ForFlowBased node with a RoutingRule node with anAccessTechnology leaf configured as the 3GPP and an AccessId leafconfigured as a CSG identity, e.g., CSG-ID1. That is, according to theprocess 40, an xml code for the ISRP node can be configured by thenetwork 111 as follows:

<X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/AccessTechnology: 3GPP<X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/AccessId: CSG-ID1

Besides, the network 111 can configure a policy node under the ISRP nodefor, e.g., a ForServiceBased node with a RoutingRule node with anAccessTechnology leaf configured as the 3GPP, and an AccessId leafconfigured as a CSG identity, e.g., CSG-ID1. That is, according to theprocess 40, an xml code for the ISRP node can be configured by thenetwork 111 as follows:

<X>/ISRP/<X>/ForServiceBased/<X>/RoutingRule/<X>/AccessTechnolo- gy:3GPP <X>/ISRP/<X>/ForServiceBased/<X>/RoutingRule/<X>/AccessId: CSG-ID1

On the other hand, two leaves, a HomeAccessID leaf and aSecondaryHomeAccessID leaf, can be newly added under thePrioritizedAccess node to avoid a situation that that the originalAccessId leaf cannot be used due to format inconsistency. When theAccessTechnology leaf is configured as the 3GPP, the HomeAccessID leafand the SecondaryHomeAccessID leaf can be configured as two CSGidentities, respectively, e.g., CSG-ID1 and CSG-ID2. That is, an xmlcode for the ISMP node can be configured by the network 111 as follows:

<X>/Policy/<X>/PrioritizedAccess/<X>/AccessTechnology: 3GPP<X>/Policy/<X>/PrioritizedAccess/<X>/HomeAccessId: CSG-ID1<X>/Policy/<X>/PrioritizedAccess/<X>/SecondaryHomeAccessId: CSG-ID2

Please note that the CSG identities CSG-ID1 and CSG-ID2, which are thevalues of the HomeAccessId leaf and the SecondaryHomeAccessId leaf,respectively, are presented as an example to demonstrate specific CSGidentities of the CSG cells. In other words, according to such policies,the UE which may be a member of the CSGs with the CSG identities CSG-ID1and/or CSG-ID2 can choose and access the CSG cells with the CSGidentities CSG-ID1 and/or CSG-ID2 when using the 3GPP as the accesstechnology. For example, if the UE is the member of the CSG with the CSGidentity CSG-ID2 but not the member of the CSG with the CSG identityCSG-ID1, it can choose and access one CSG cell with the CSG identityCSG-ID2. Please note that, when configuring a policy (i.e., a policynode) with a specific CSG identity for the UE, the network 111 candecide if the CSG membership of the UE should be considered. The UE candetermine the validity of the policies based on its membership of aspecific CSG with a CSG identity.

Please refer to FIG. 6, which is a schematic diagram of a policy node 60according to an example of the present invention. FIG. 6 is used forillustrating configuration (e.g., modification and addition) of nodesand leaves corresponding to the xml code. As shown in FIG. 6, theAccessTechnology leaf 600, the HomeAccessID leaf 602 and theSecondaryHomeAccessID leaf 604 are configured (i.e., specified) as the3GPP, CSG-ID1, and CSG-ID2, respectively.

Besides, the network 111 can also configure a new leaf CSGId under a3GPP_Location node of a ValidityArea node for the ISMP node, forconfiguring a CSG identity. That is, an xml code for the ISMP node canbe configured by the network 111 as follows:

<X>/Policy/<X>/ValidityArea/3GPP_Location/<X>/CSGId?

As shown in FIG. 5, the leaf CSGId can be configured under the3GPP_Location node 504. Similarly, the leaf CSGId is configured underthe 3GPP_Location node 606 in FIG. 6.

On the other hand, the network 111 can further provide discoveryinformation for the UE by configuring a new leaf CSGId under a3GPP_Location node of an AccessNetworkArea node for aDiscoveryInformation node, for configuring a CSG identity. That is, anxml code for the DiscoveryInformation node can be configured by thenetwork 111 as follows:

<X>/DiscoveryInformation/<X>/AccessNetworkArea/3GPP_Loca- tion/<X>/CSGId?

Please refer to FIG. 7, which is a schematic diagram of aDiscoveryInformation node 70 according to an example of the presentinvention. FIG. 7 is used for illustrating configuration (e.g.,modification and addition) of nodes and leaves corresponding to the xmlcode. As shown in FIG. 7, the CSGId leaf is configured under the3GPP_Location node 700. Thus, the UE can discover the CSG cells (e.g.,femtocells in a home access network) with the specified CSG identityaccording to the newly added leaf CSGId.

Besides, the network 111 can provide location information of a UE to theUE by configuring a new leaf CSGId under a 3GPP_Location node for aUE_Location node, for configuring a CSG identity. That is, an xml codefor the UE_Location node can be configured by the network 111 asfollows:

<X>/UE_Location/3GPP_Location/<X>/CSGId?

Please refer to FIG. 8, which is a schematic diagram of a UE_Locationnode 80 according to an example of the present invention. FIG. 8 is usedfor illustrating configuration (e.g., modification and addition) ofnodes and leaves corresponding to the xml code. As shown in FIG. 8, theleaf CSGId is configured under the 3GPP_Location node 800. Thus, thenetwork 111 can provide the location information of the UE in terms of aspecific value of the CSGId, i.e., a CSG identity, which indicates theUE that it locates in coverage of CSG cells with the CSG identity.

On the other hand, a CSG identity may also be configured under a nodewhich is newly added under the PrioritizedAccess node. For example,please refer to FIG. 9, which is a schematic diagram of a policy node 90according to an example of the present invention. FIG. 9 is used forillustrating configuration (e.g., modification and addition) of nodesand leaves. As shown in FIG. 9, the HomeAccess node 900 is newly addedfor configuring a new leaf CSGId.

Note that a criterion according to which the network 111 determines aplurality of CSG cells with a specific CSG identity for the UE is notlimited. For example, the CSG cells that the UE can access can bedetermined according to whether the UE is a member of the CSG with theCSG identity, UE's subscription or an operator configuration of thewireless communication system.

Thus, according to the process 40 and the above description, when thenetwork 111 determines the 3GPP as an access technology for the UE, thenetwork 111 can configure a policy (i.e., a policy node) with the 3GPPand a CSG identity of a plurality of CSG cells, to indicate the policyto the UE. As a result, the UE can communicate with the EPC network viaone or more of the CSG cells with the CSG identity. When the UE movesaround and handover between CSG cells, it does not need to re-evaluatepolicies for finding a better policy for accessing the network 111.

Please refer to FIG. 10, which is a flowchart of a process 100 accordingto an example of the present invention. The process 100 is utilized inthe network 111 (i.e., the ANDSF server therein) shown in FIG. 1, forhandling the ANDSF shown in FIG. 2, to provide routing policies to a UE,for the UE to get a 3GPP access via a CSG cell with a specific CSGidentity and to have an L-GW providing a PDN connection via a specificAPN. The process 100 may be compiled into the program code 314 andincludes the following steps:

Step 1000: Start.

Step 1002: Determine a plurality of CSG cells of the wirelesscommunication system with the same CSG identity, for the UE to access aservice indicated by an access point name (APN) of the wirelesscommunication system via the plurality of CSG cells with the same CSGidentity, after the network 111 determines the 3GPP as an accesstechnology for the UE.

Step 1004: Configure an ISMP node such that a value of anAccessTechnology leaf of a PrioritizedAccess node is configured as the3GPP, a value of an AccessId leaf of the PrioritizedAccess node isconfigured as the same CSG identity of the plurality of CSG cells, and aPrioritizedAPN node is configured under the ISMP node.

Step 1006: End.

According to the process 100, the network 111 first determines aplurality of CSG cells of the wireless communication system with thesame CSG identity, for the UE to access a service indicated by an APN ofthe wireless communication system via the plurality of CSG cells withthe same CSG identity, after the network determines the 3GPP as anaccess technology for the UE. Then, the network 111 configures an ISMPnode such that a value of an AccessTechnology leaf of aPrioritizedAccess node is configured as the 3GPP, a value of an AccessIdleaf of the PrioritizedAccess node is configured as the same CSGidentity of the plurality of CSG cells, and a PrioritizedAPN node isconfigured under the ISMP node. That is, assuming that the value of theAccessId leaf is CSG-ID1 and an APN APN1 is configured under thePrioritizedAPN node, an xml code for the policy node can be configuredby the network 111 as follows:

<X>/Policy/<X>/PrioritizedAccess/<X>/AccessTechnology: 3GPP<X>/Policy/<X>/PrioritizedAccess/<X>/AccessId: CSG-ID1<X>/Policy/<X>/PrioritizedAPN/<X>/<X>/Policy/<X>/PrioritizedAPN/<X>/APN: APN1

Please note that, a PrioritizedAPN node can also be newly added underthe PrioritizedAccess node for configuring the APN APN1 as follows:

<X>/Policy/<X>/PrioritizedAccess/<X>/AccessTechnology: 3GPP<X>/Policy/<X>/PrioritizedAccess/<X>/AccessId: CSG-ID1<X>/Policy/<X>/PrioritizedAccess/<X>/PrioritizedAPN: APN1

Furthermore, more leafs, e.g., a FirstAPN leaf and a SecondaryAPN leaf,can be configured under the PrioritizedAPN node, to configure the ISMPnode with more APN information. For example, assuming that the value ofthe AccessId leaf is CSG-ID1 and two APNs APN1 and APN2 are suggestedfor connection, an xml code for the policy node can be configured by thenetwork 111 as follows:

<X>/Policy/<X>/PrioritizedAccess/<X>/AccessTechnology: 3GPP<X>/Policy/<X>/PrioritizedAccess/<X>/AccessId: CSG-ID1<X>/Policy/<X>/PrioritizedAPN/<X>/<X>/Policy/<X>/PrioritizedAPN/<X>/FirstAPN: APN1<X>/Policy/<X>/PrioritizedAPN/<X>/SecondaryAPN: APN2

Besides, the FirstAPN leaf and the SecondaryAPN leaf can also beconfigured under the PrioritizedAccess node for providing more APNinformation to the UE as follows:

<X>/Policy/<X>/PrioritizedAccess/<X>/AccessTechnology: 3GPP;<X>/Policy/<X>/PrioritizedAccess/<X>/AccessId: CSG-ID1;<X>/Policy/<X>/PrioritizedAccess/<X>/PrioritizedAPN/<X>/FirstAPN: APN1<X>/Policy/<X>/PrioritizedAccess/<X>/PrioritizedAPN/<X>/ SecondaryAPN:APN2

Please note that, even though the policy node is used in the examplesfor illustrating the present invention, the policy node can be replacedby the other policy nodes including the ForFlowBased node, theForServiceBased node or the ForNonSeamlessOffload node. For example, thenetwork 111 can configure a policy (i.e., a policy node) under the ISRPnode for a ForServiceBased node with a RoutingRule node with anAccessTechnology leaf configured as the 3GPP, an AccessId leafconfigured as a CSG identity, e.g., CSG-ID1, and a value of an APN leafof a PrioritizedAPN node is APN1. That is, according to the process 100,an xml code for the ISRP node can be configured by the network 111 asfollows:

<X>/ISRP/<X>/ForServiceBased/<X>/RoutingRule/AccessTechnology: 3GPP<X>/ISRP/<X>/ForServiceBased/<X>/RoutingRule/AccessId: CSG-ID1<X>/ISRP/<X>/ForServiceBased/<X>/PrioritizedAPN/<X>/<X>/ISRP/<X>/ForServiceBased/<X>/PrioritizedAPN/<X>/APN: APN1

As shown in FIG. 5, two newly added leaves, i.e., a FirstAPN leaf and aSecondaryAPN leaf, are configured under a PrioritizedAPN node 506.Similarly, two newly added leaves, i.e. a FirstAPN leaf and aSecondaryAPN leaf, can be configured under a PrioritizedAPN node 608 inFIG. 6. For example, assume that a UE has a PDN connection associated tothe APN APN1 via a P-GW in the EPC network. A home network with a L-GWcan provide a PDN connection associated to the APN APN2. That is, thenetwork 111 can provide the routing policies for the PDN connection viathe APN APN2 as follows:

<X>/ISRP/<X>/ForServiceBased/<X>/APN: APN1<X>/ISRP/<X>/ForServiceBased/<X>/RoutingRule/AccessTechnology: 3GPP<X>/ISRP/<X>/ForServiceBased/<X>/RoutingRule/AccessId: CSG-ID1<X>/ISRP/<X>/ForServiceBased/<X>/PrioritizedAPN/<X>/APN: APN2

Hence, when the UE is handover from a macrocell to a CSG cell, the UEcan route its PDN connection from the P-GW in the EPC network to theL-GW in the home network.

On the other hand, a HomeAccessID leaf can be newly added under aPrioritizedAccess node for configuring a CSG identity, e.g., CSG-ID1, toavoid a situation that that the original AccessId leaf cannot be useddue to format inconsistency. That is, an xml code for the policy nodecan be configured by the network 111 as follows:

<X>/Policy/<X>/PrioritizedAccess/<X>/AccessTechnology: 3GPP<X>/Policy/<X>/PrioritizedAccess/<X>/HomeAccessId: CSG-ID1<X>/Policy/<X>/PrioritizedAPN/<X>/<X>/Policy/<X>/PrioritizedAPN/<X>/APN?

Please note that, even though the policy node is used in the examplesfor illustrating the present invention, the policy node can be replacedby the other policy nodes including the ForFlowBased node, theForServiceBased node or the ForNonSeamlessOffload node. For example, thenetwork 111 can configure a policy (i.e., a policy node) under the ISRPnode for a ForServiceBased node with a RoutingRule node with anAccessTechnology leaf configured as the 3GPP, and a HomeAccessID leafand a SecondaryHomeAccessID leaf configured as two CSG identities, e.g.,CSG-ID1 and CSG-ID2, respectively. A value of an APN leaf of aPrioritizedAPN node is APN1. That is, according to the process 40, anxml code for the ISRP node can be configured by the network 111 asfollows:

<X>/ISRP/<X>/ForServiceBased/<X>/RoutingRule/AccessTechnology: 3GPP<X>/ISRP/<X>/ForServiceBased/<X>/RoutingRule/HomeAccessId: CSG-ID1<X>/ISRP/<X>/ForServiceBased/<X>/RoutingRule/<X>/ SecondaryHomeAccessId:CSG-ID2 <X>/ISRP/<X>/ForServiceBased/<X>/PrioritizedAPN/<X>/APN: APN1

Thus, according to the process 100 and the above description, thenetwork 111 can provide routing policies to the UE, such that the UE canroute its PDN connection from an original APN (associated to an originalPDN) to the determined APN (associated to a new PDN), wherein the UEcommunicates with the original APN and the determined APN via a P-GW andan L-GW, respectively.

Please refer to FIG. 11, which is a flowchart of a process 110 accordingto an example of the present in invention. The process 110 is utilizedin the network 111 (i.e., the ANDSF server therein) shown in FIG. 1, toconfigure routing policies to a UE. The process 110 may be compiled intothe program code 314 and includes the following steps:

Step 1100: Start.

Step 1102: Determine an IP flow of the UE which is with a PDN connectionassociated to an APN of the wireless communication system, for the UE toroute the IP flow.

Step 1104: Configure an ISRP policy for a ForFlowBased node such that avalue of an AccessTechnology leaf of a RoutingRule node is configured asthe 3GPP, a value of an AccessId leaf is configured as a CSG identity ofa plurality of CSG cells, and a PrioritizedAPN node is configured undera policy node for configuring the APN.

Step 1106: End.

According to the process 110, the network 111 determines an IP flow ofthe UE which is with a PDN connection associated to an APN of thewireless communication system, for the UE to route the IP flow. Then,the network 111 configures an ISRP policy for a ForFlowBased node suchthat a value of an AccessTechnology leaf of a RoutingRule node isconfigured as the 3GPP, a value of an AccessId leaf is configured as aCSG identity of a plurality of CSG cells, and a PrioritizedAPN node isconfigured under a policy node for configuring the APN, for the UE toroute the IP flow.

In detail, the policy node can be the ForFlowBased node if the accesstechnology is the 3GPP, and the policy node can be theForNonSeamlessOffload node if the access technology is the wirelesslocal area network (WLAN). For example, when the access technology isthe 3GPP and a specific IP flow IPflow1 is considered, an xml code forthe ISRP node can be configured by the network 111 as follows:

<X>/ISRP/<X>/ForFlowBased/<X>/IPFlow/<IPflow1><X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/AccessTechnology: 3GPP<X>/ISRP/<X>/ForFlowBased/<X>/PrioritizedAPN/<X>/APN: APN1

When the access technology is the WLAN and a specific IP flow IPflow1 isdetermined, an xml code for the ISRP node can be configured by thenetwork 111 as follows:

<X>/ISRP/<X>/ForNonSeamlessOffload/<X>/IPFlow/<IPflow1><X>/ISRP/<X>/ForNonSeamlessOffload/<X>/RoutingRule/<X>/AccessTechnology: WLAN<X>/ISRP/<X>/ForNonSeamlessOffload/<X>/PrioritizedAPN: APN1

Furthermore, more leaves, e.g., a FirstAPN leaf and a SecondaryAPN leafcan be configured under a PrioritizedAPN node, to provide a policy(i.e., a policy node) with more APN information. For example, assumingthat values of the two APNs leaves suggested for connection are APN1 andAPN2, an xml code for the policy node can be configured by the network111 as follows:

<X>/ISRP/<X>/ForFlowBased/<X>/IPFlow/<IPflow1><X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/AccessTechnology: 3GPP<X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/PrioritizedAPN/<X>/ FirstAPN:APN1 <X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/PrioritizedAPN/<X>/Secondary APN: APN2

In this example, the UE can distribute (i.e., route) an IP flow IPflow1to a 3GPP access with a PDN connection associated to an APN APN1 as thefirst option or an APN APN2 as the second option, if the UE has no PDNconnection associated to the APN APN1.

For example, assuming that values of two APNs leaves suggested forconnection are APN1 and APN2, an xml code for the policy node can beconfigured by the network 111 as follows:

<X>/ISRP/<X>/ForNonSeamlessOffload/<X>/IPFlow/<IPflow1><X>/ISRP/<X>/ForNonSeamlessOffload/<X>/RoutingRule/<X>/AccessId: SSID1<X>/ISRP/<X>/ForNonSeamlessOffload/<X>/RoutingRule/PrioritizedAPN/<X>/FirstAPN: APN1<X>/ISRP/<X>/ForNonSeamlessOffload/<X>/RoutingRule/PrioritizedAPN/<X>/SecondaryAPN: APN2

In this example, the UE can distribute (i.e., route) an IP flow IPflow1to a WLAN access via a WLAN access point with a SSID configured asSSID1, and the WLAN access can provide a PDN connection associated to anAPN APN1 as the first option or an APN APN2 as the second option if theUE has no PDN connection associated to the APN APN1.

Please note that, in the above xml codes, the APN is configured under aPrioritizedAPN node which is newly added under the RoutingRule node ofthe ForFlowBased node or the ForNonSeamlessOffload node. However, aparent node under which the APN is configured not limited. For example,the PrioritizedAPN node can be added as a new leaf under the RoutingRulenode as follows:

<X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/PrioritizedAPN: APN1<X>/ISRP/<X>/ForNonSeamlessOffload/<X>/RoutingRule/<X>/ PrioritizedAPN:APN1

Please note that, a single IP flow is illustrated in the abovedescription. However, the present invention can be applied to multipleIP flows. For example, for a UE with both of 3GPP access and WLANaccess, the network 111 can provide policies, for the UE to use the 3GPPaccess to route two IP flows IPflow1 and IPflow2 to an APN APN1 (e.g.,via a P-GW) and an APN APN2 (e.g., via a L-GW), respectively.Alternatively, the network 111 can provide policies, for the UE to usethe WLAN access with a specific SSID, e.g., SSID1, to route one IPflow,e.g., IPflow3, via the specific WLAN which can provide a PDN connectionassociated to an APN APN3. Accordingly, an xml code for the ISRP nodecan be configured by the network 111 as follows:

<X>/ISRP/<X>/ForFlowBased/<X>/IPFlow/<IPflow1><X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/AccessTechnology: 3GPP<X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/PrioritizedAPN: APN1<X>/ISRP/<X>/ForFlowBased/<X>/IPFlow/<IPflow2><X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/AccessTechnology: 3GPP<X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/PrioritizedAPN: APN2<X>/ISRP/<X>/ForFlowBased/<X>/IPFlow/<IPflow3><X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/AccessTechnology: WLAN<X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/AccessId: SSID1<X>/ISRP/<X>/ForFlowBased/<X>/RoutingRule/<X>/PrioritizedAPN: APN3

Thus, according to the process 110 and the above description, thenetwork 111 can provide routing policies to the UE, such that the UE canroute one or more IP flows to one or more APNs, wherein the UEcommunicates with the one or more APNs via a P-GW or an L-GW.

According to the above description, the network 111 can determine andconfigure at least one policy node, including the ISMP node, theForFlowBased node and the ForNonSeamlessOffload node, and transmits theat least one policy node to the UE. After receiving the at least onepolicy node from the network 111, the UE can select one of the at leastone policy node, for communicating with the network 111 (e.g., the EPCnetwork therein or WLAN with or without a specific SSID) by usinginformation (e.g., APN and/or CSG identity) indicated in the one of theat least one policy node, e.g., the ISMP node, the ForFlowBased node andthe ForNonSeamlessOffload node.

Please refer to FIG. 12, which is a flowchart of a process 120 accordingto an example of the present invention. The process 120 is utilized inthe UE shown in FIG. 1, for handling the policies received from thenetwork 111. The process 120 may be compiled into the program code 314and includes the following steps:

Step 1200: Start.

Step 1202: Receive at least one policy from the network 111.

Step 1204: Check a RoutingCriteria node for location of the UE, fordetermining validity criteria of a policy according to anAccessTechnology node of a RoutingRule node, to select at least onevalid policy from the at least one policy.

Step 1206: Select one of the at least one valid policy, forcommunicating with the network 111.

Step 1208: End.

According to the process 120, after the UE receives at least one policyfrom the network 111, the UE checks a RoutingCriteria node for locationof the UE, for determining validity criteria of a policy according to anAccessTechnology node of a RoutingRule node, to select at least onevalid policy from the at least one policy. Then, the UE can select oneof the at least one valid policy, for communicating with the network111. In other words, after the UE receives at least one policy from thenetwork 111, the UE checks RoutingCriteria for location of the UE, e.g.,3GPP location with a specific CSG identity, as a policy validitycriteria according to an indicated AccessTechnology of a RoutingRulenode, e.g., an AccessTechnology node indicates 3GPP access and anAccessId node indicates a CSG identity, e.g., CSG-ID1. For example, ifthe UE is located in a 3GPP access coverage of a CSG cell with a CSGidentity CSG-ID1, the policy is considered valid. Then, the UE canselect one of the valid policies, for communicating with the network111.

Those skilled in the art should readily make combinations, modificationsand/or alterations on the abovementioned examples. The abovementionedsteps of the processes including suggested steps can be realized bymeans that could be a hardware, a firmware known as a combination of ahardware device and computer instructions and data that reside asread-only software on the hardware device, or an electronic system.Examples of hardware can include analog, digital and mixed circuitsknown as microcircuit, microchip, or silicon chip. Examples of theelectronic system can include a system on chip (SOC), system in package(SiP), a computer on module (COM), and the communication device 30.

To sum up, the present invention provides a method of handling an ANDSFfor the network. The network can configure and provide the ANDSF to aUE. Then, the UE can determine a CSG cell according to the ANDSFprovided by the network. Further, the UE can determine how to route aPDN connection and an IP flow according to the ANDSF provided by thenetwork.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A method of handling an access network discoveryand selection function (ANDSF) for a network of a wireless communicationsystem, the method comprising: determining a first plurality of closedsubscriber group (CSG) cells of the wireless communication system with afirst CSG identity when a mobile device is a CSG member and locates incoverage of a macro evolved universal terrestrial radio access (EUTRA)cell and the first plurality of CSG cells with the first CSG identity,for the mobile device of the wireless communication system tocommunicate with an evolved packet core (EPC) network of the wirelesscommunication system via the first plurality of CSG cells, after thenetwork determines the 3rd Generation Partnership Project (3GPP) as anaccess technology for the mobile device; and configuring an inter-systemmobility policy (ISMP) node such that a value of an AccessTechnologyleaf of a PrioritizedAccess node is configured as the 3GPP, and a valueof a first AccessId leaf of the PrioritizedAccess node is configured asthe first CSG identity of the first plurality of CSG cells.
 2. Themethod of claim 1, wherein the ISMP node is a policy node, aForFlowBased node of an inter-system routing policy (ISRP) node or aForServiceBased node of the ISRP node.
 3. The method of claim 2, whereinthe PrioritizedAccess node is a RoutingRule node, when the ISMP node isthe ForFlowBased node.
 4. The method of claim 2, wherein thePrioritizedAccess node is a RoutingRule node, when the ISMP node is theForServiceBased node.
 5. The method of claim 1, further comprising:determining a second plurality of CSG cells of the wirelesscommunication system with a second CSG identity, for the mobile deviceto communicate with the EPC network via the second plurality of CSGcells; and configuring the ISMP node such that a value of a secondAccessId leaf of the PrioritizedAccess node is configured as the secondCSG identity of the second plurality of CSG cells.
 6. The method ofclaim 1, wherein the first AccessId leaf is configured under thePrioritizedAccess node, for configuring the first CSG identity.
 7. Themethod of claim 1, further comprising: arranging a new leaf under a3GPP_Location node of a ValidityArea node of the ISMP node, forconfiguring the first CSG identity.
 8. The method of claim 1, furthercomprising: arranging a new leaf under a 3GPP_Location node of anAccessNetworkArea node of a DiscoveryInformation node, for configuringthe first CSG identity.
 9. The method of claim 1, further comprising:arranging a new leaf under a 3GPP_Location leaf of a UE_Location node,for configuring the first CSG identity.
 10. The method of claim 1,wherein the first plurality of CSG cells are determined according to aCSG membership of the mobile device, a user's subscription of a user ofthe mobile device or an operator configuration of the wirelesscommunication system.